Helping people out, acts of kindness and good deed are awesome; but there's more to it than that!
What affects whether a person feel gratitude or not? If the they feel more gratitude or less gratitude.
There are 2 factors that affect how you feel gratitude when others perform good deeds:
1. Perceived intention of the benefactor (the one doing the good deed)
2. The perceived value, or the cost to the benefactor
So if you are out there doing a "good deed" that is really to benefit you - people know that, including your kids!
For a person to feel the most gratitude for a good deed they need to know the intention of the person was pure , they really are trying to help and not simply for selfish reasons. And there is a value to the good deed or cost to the benefactor; whether that be time, money or energy.
The next time you do a good deed - evaluate how the person receiving it will look at the intention and the value.